It is generally agreed at early diagnosis of cancer is almost always a prerequisite of successful treatment. For example, the WHO Expert Committee's Report on Early Detection of Cancer (1969) stated that over half of cancer patients could have been cured if the disease had been detected at an early stage and treated soon after detection. In view of the widespread incidence of the disease, mass screening techniques would evidently be of great value, such as is available, for example, at least in developed countries, in the field of tuberculosis of the chest by means of mass X-ray examination.
Among previous proposals for the diagnosis of cancer may be mentioned the following. In U.S. Pat. No. 3,476,514 there was described a method of detecting cancer cells by staining test cells with acriflavine-HCl solution, determining indirectly the dye absorbed by the test cells and comparing with a control JP 56166124A2 proposed a method for diagnosing malignant tumors which utilized an injectable composition containing an endotoxin extracted from cultured bacteria. In GB 1587244, there was described inter alia, the use in a serum agglutination test on the sera of patients, for the detection of neoplasm, of an antigen produced by a species of the genus Streptococcus. 
Bodily health is known to be affected by the nature of the intestinal flora which apparently influences, for example, metabolic processes and both local and general body immune response. It has also been known for some time that certain of the intestinal flora bacteria of normal humans have oncolytic activity, and that there exists a relationship between intestinal microfloral composition and cancer morbidity, see e.g., Oleynik, S. F. and Panchishina, M. V., “About Coliflora and Cancerolycity and Carcinogenicity of the intestine”, Vrachebnoye-delo, 5:13-17 (1968).
There are several publications relating to the use of fecal samples for the detection of cancer. For example, EP 685739 described a method for the diagnosis of colorectal cancer comprising reaction anti-DAF antibodies with a supernatant of a fecal sample thereby forming an antigen-antibody complex and measuring the amount of complex formed. Another publication is U.S. Pat No. 5,952,200 which describes a test for diagnosing the presence of cancerous cells in samples of human tissue, fluids or semi-fluids such as feces, by the detection of transcripts for stromelysin0-3 in the tissue cells.
JP 6258324 describes a method for the diagnosis of digestive-system cancer disease by using an antibody selective to variation-type protein of the cancer-suppressing gene P53, while U.S. Pat. No. 5,455,160 describes a method for determination of fecal calprotectin as a parameter for monitoring Inflammatory Bowel Disease and gastrointestinal cancer.
Finally, U.S. Pat. No. 5,344,762 describes a method for early diagnosis of cancer by incubating in vitro a human fecal sample including bacteria with a standard culture of a known number of cancer cells. After a time period the number of cancer cells interacted and non-interacted with the bacteria is counted and the results are used for determination of a disease state.